\chapter{Acknowledgments}

The master thesis was a result of the collaboration with User Experience Department of Siemens Corporate Research (SCR) in Princeton, America.

First of all, I would like to thank Mr. Claus Knapheide, the director of User Experience Department, for giving me the trust and chance to start the thesis.

Also I would like to thank Prof. Hunger for the guide from the university, and Mr. Robert Rauschenberger for the supervision at the side of SCR. Both of them always gave me the encouragement and support during the compilation of the thesis.  

Further I want to thank all the colleagues in User Experience Department of SCR for the creative and pleasant work atmosphere and the successful teamwork. Especially I want to thank Mr. Sam Zheng for all the inspiring conversations, patient guides and valuable advices. 

\begin{flushright}
21.Jan, 2008 in Duisburg \textit{Mo Wang}
\end{flushright}
